Laptops :: Avoiding PCMCIA device conflicts with serial

This is advice, not a question. I had a problem with my Sony notebook's internal modem not working on occasions, until I discovered that whenever a PCMCIA card was in place, it was allocated irq 3, which is the required irq for my modem (/dev/ttyS1).
The fix is simple. In /etc/pcmcia/config.opts uncomment the line #exclude irq 3 . You might want to add some lines excluding other irq's as well if those irq's are required by devices which won't share their irq. Use cat /proc/interrupts and dmesg to diagnose.
I hope this helps others.
Craig S

Cool great find...thanks for posting up here bud

Brian
AwPhuch

original here.